<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <link rel="stylesheet" href="style.css"/>
    <title></title>
    <style>
        .big{
            background: url("images/img01.jpg");
        }
        .header{
            width: 940px;
            height:150px;
            margin: auto;
            background: red;
        }
    </style>
</head>
<body>
<div class="big">
    <div class="header">

    </div>
</div>
</body>
</html>